1. Field of the Invention
The present invention relates to case packing systems and, more particularly, it relates to a robotic case packing system for loading articles from a moving conveyor belt or similar moving conveyor system into a container such as a corrugated cardboard box.
2. Description of Related Art
For many years, attempts have been made to develop improved systems for picking up individual articles of product from a conveyor belt or similar moving conveyor system and depositing those articles within a container such as a corrugated cardboard box. The issues presented include how to accomplish this task, with both the desired speed and the desired accuracy. To meet the demand for speed, past solutions have included incorporation of multiple robots along the conveyor. For example, see the device described in applicant's U.S. Pat. No. 6,540,063, which patent is fully incorporated herein by reference. Often, if four such robot heads were used, each head would pick up every fourth article of product in a conveying system in a staggered manner such that the four robot heads effectively removed four consecutive articles of product during each iteration. While this multiplicity of heads did provide for a multiplying of speed, the means for moving the robot heads from the conveying belt and to the container were often awkward or cumbersome in implementation. Similarly, such systems were sometimes limited to loading cases only in multiples of the number of heads within the system. For example, if four heads were used, a case could be loaded with four, eight, or twelve articles; but it could not be loaded with seven or fifteen articles without complex programming or a drop in efficiency.
To provide greater flexibility, multi-axis robots have been developed for picking an article off of a common belt. Many such multi-axis robots, however, have proven to be fairly slow and heavy. Hence, while such robots may provide greater flexibility in motion, they have also provided a need for an even greater number of robots to meet the speed requirements in the marketplace today. Additionally, it has been found that with some three-axis robots, the range of movement may be limited in certain directions. For example, certain three-axis robots are very limited in their vertical component, which can make movement of a bag from a conveying belt into a deep container difficult.
Moreover, while two-axis robots provide a desired range of horizontal and vertical motion in a single plane, such robots do not generally accommodate three dimensional movement of an article from a conveyor belt over and down into a container unless the third element of motion is otherwise provided. To address this problem, attempts have been made to move a two-axis robot back and forth on linear slides to thereby introduce the third element of motion. This approach, however, appears to limit operating speed and increase the cost of the structure.
It is therefore desirable to provide an improved system that has the desired speed of operation with the desired range of movement, and that accurately picks articles of product from a conveying system and places them into a container.